Sorry to raise a question that has been around before, but I can't find a definitive answer. My original paper manual for my 3GMD (which covers the 1, 2 and 3 GM's and 3HM) has a separate note specifically for the 3GMD engine alone, that the oil in the tranny is different from the oil used in the engine and a warning to use the proper oil, and refers me to a chart on another page. That chart shows the engine oil and tranny oil to be the same for the 1, 2 and 3GM, while the 3HM uses Dexron. I also have a downloaded version of the 3GMD manual, and it has the same note, but no cross reference or any reference at all to the specific oil to be used in the tranny. In the downloaded version, the note is explicit in saying that the 3GMD and 3HM use different tranny oil than the engine, although there is no oil spec that i can find in that manual.
Does anyone have a source for a definitive answer on the tranny oil (engine oil or Dexron)?
Also, interesting definition of how to measure the tranny oil level in both versions of the manual: ".....check with screwing the dipstick". I understand that the common consensus is that this means to unscrew the dipstick and leave it resting on the top of the threads, but hard to get that from the written words